Signments



(No Model.)

G. W. GUY.

TELEPHONE EXCHANGE SYSTEM. No. 257,664. Patented May 9, 1882.

' UNITED' STATES PATENT ()FFIGEG' GEORGE \V. COY, OF MILFORD, CONNECTICUT, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO THE UNITED STATES TELEPHONE MANUFACTURING COMPANY, OF YORK, N. -Y.

TELEPHONE-EXCHANGE SYSTEM.

SPECIFICATION forming'part of Letters Patent No. 257,664, dated-May 9, 1882.

Application filed December 31, 1880, (No model.)

To all whom it may concern Be it known that I, GEO. W. GoY, a citizen of the United States, residing at Milford, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Telephone Exchange Systems; and I do hereby declare the following to be a full, clear, and exact, description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompan'ying drawing, and toletters or figures of reference marked thereon, which forms a part of this specification. Q

My invention relates to telephone-exchange apparatus, the object being to facilitate the operation of placing subscribers in communication, To this end my invention consists in certaincombinations of apparatus, which will be particularly described, and then pointed out in the claims.

4 In the accompanying drawing I have shown my invention applied to a system in which a listening-telephone normally connected to the several lines is used at thecentral office, and

resistances are placed at the subscribers stations to prevent the diversion of the telephonic currents coming from a subscriber-s station to the central oflice telephone. I do not, however, claim the arrangement of the resistances orthe particular arrangement of the receiv ing-telephone with relation to the lines as my invention, and I wish it to be understood that the particular invention herein claimed may 3 5 be used in conjunction with other arrangement of those devices besides those shown.

The'drawing is a diagram of the central-officeapparatus and the devices used at themrious subscribers stations. But two stations 40 are represented for the sake of simplicity.

B, connected through a listening-telephone, L T, with the ground. Drop-annunciators, one in each line-circuit, are shown at W. The lines 1 2 8 are connected to the annunciators through circuit-shifting apparatus K. Said boards may be operated so as to connect any line-wire to a branch wire leading to a generator of electricity common to said lines, (represented at M B as a battery,) when it is desired to signal from the central ot'fice to a subscriber.

The apparatus at the subscribers station consists of an ordinary two-point switch, S S one of whose studs connects through wire 9, secondary of the induction-coil in. transmitter M, and'wire 10 with the ground E. The other stud connects through call-bell H with a car bon resistance, 0, or other form, of resistance free from self-induction, and with the ground;

A circuit-shifting apparatus, K, serves to break the connection of the line 1 with the switch S and make a connection through wire 13 with one pole of the local transmitter-battery L, the other pole of which hasan earth connection. When this is done the current from the battery circulates over the line and through the drop-amiunciator, thus causing the drop of the annunciator to fall to indicate the line from which the signal comes.

The battery I is connected, as usual, with contact-points ot" the transmitter and the primary of the induction-coil, and by this arrangement is made to serve both the purpose of a local battery for the transmitter and a signaling-battery for signaling to the central otfice.

Each suhscribers station is to be provided with devices substantially the same as those.

just described as connected with linel.

The circuit from each subscribers station to the central office and annunciator is normally through the subscribers hell or main line andswitch K to the line-strip of the switch-board,

and to ground through the telephone at the central office.

At the subscribers station the line isnor-f mally connected to the earth through the circuit-shifting apparatus K, switch-lever S, callbell H, and resistance 0.

By turning the switch-lever S, so as to connect the line to earth through his telephone, the subscriber may inform the listenin g. operator of the connection desired.

The resistances G in the several lines serve to prevent the diversion of the telephonic currents' which would otherwise take place through the bar B and the strips connected to the leading to the electric generator, and rings the bell at that subscribers station. He then shifts the plugs at the bottom of the line-strips to any one of the horizontal connecting-strips not in use, which act disconnects the lines from the telephone L T, and connects them when the annunciators are located on the normal line eircuits at the point here shown through said annunciators. cuit-shifter K will in the above arrangement disconnect the line from the circuit leading to the annunciator and normal ground, thereby preventing the current of the generator M B from passing to earth at the central office or from affecting the annunciator-card. When the subscribers have finished their communication the circuit-shifting apparatus at either station may be operated soas'to throw battery L to line, upon which the annunciator-d reps in the connected linesare made to fall, giving jnotice at the central ofiice that the lines are to be disconnected.

Instead of the apparatus used on line 1 for connecting the local battery to line, when it is desired to operate the annunciator in the .direct line circuit at the central otfice, I may employ other devices-as, for instance, apparatus such as that shown on line 2, where M E represent a magneto-electric machine or generator of any preferred construction, to the box of which is attached an electromagnetic callbell for receiving the signal from the central ofiice. A push-button, which serves to throw the coils of the machine into circuit, and, if desired, to simultaneously throw out the bell, is indicated at p.

Other 'forms of switches and connecting apparatus may be used at the central office and at the subscribers stations in place of those shown. The forms indicated have been adopt.-

The operation of the cir-- in other locations as well as in that described with relation to the connecting apparatus, circuit-shifters, lines, &c., without departingfrom the spirit of the invention. I do not herein make any claim to the combination of a central-offiee telephone-switch and a disconnecting annu-neiator interposed between two connected lines for the purpose of notifying the central-office operator to disconnect the line upon the discontinuance of conversation, as this forms the subject ofa division of the presentapplication nor does thecombination at acentral office of aline connecting two subscribers witha signaling device located in saidline, whereby the operator may be notified to disconnect the subscribers lines upon the discontiuuance of conversation, form any portion of the present invention.

The particular arrangement herein shown ofa disconnecting annunciator with relation to the switch-board and the circuit-shifters, whereby the operation of signaling to a line after the two lines are connected does not affeet the annuneiator, is reserved for the subject of another application.

I do not claim the employment of carbon resistances in the manner set forth in this specification for the purpose of preventing the diversion from a common listening-telephone of the telephonic currents coming from a subscri'bers station.

\Vhat I claim'as my invention is- 1. The combination, substantially as described, of a series of telephone-lines centering in a single oflice, switch apparatus for connectin-g any two of said lines for telephonic communication, an an-nunciator in each normal line-circuit and in direct connection with said circuit, and circuit-shifting apparatus for connecting any line at pleasure to a wire leading to an electric generator for signaling to a subscribers station.

2. The combination, substantially as described, ot' a series of telephone-lines, a common switch apparatus for connecting any two lines for telephonic communication, an annunciator at thecentral ofiice placed directly in each normal line-circuit, an electric generator in a branch line for signaling purposes, and circuitshifting apparatus for disconnecting any line from the portion ofits normal circuitrunning to the annunciator and ground and connecting said line to the wire leading to the generator.

3.. In a station telephone apparatus, a battery in a local circuit, in combination with a switch in the line having connections to the station apparatus and the local battery, and acting to disconnect the line from the station apparatus and connect it with the local battery, substantially as and for the purpose described.

In testimony whereof I affix my signature in presence of two witnesses.

WVitnesses: GEORGE IV. (JOY.

H. O. TOWNSEND, THOMAS W. PEYTON. 

